1. Field of the Invention
The present invention generally relates to a semi-permeable membrane and, more particularly, to a biocompatible semi-permeable membrane. The present invention also relates to a method of manufacturing the semi-permeable membrane thereof.
2. Description of the Related Art
The dialysis membrane is the most important component of the dialyzer, also known as the artificial kidney. Generally, a semi-permeable membrane is used as the dialysis membrane. In hemodialysis, the patient's blood is pumped through the blood compartment of the dialyzer, exposing it to the semi-permeable membrane. Through the process known as diffusion, small molecules such as urea move along the concentration gradient through the semi-permeable membrane, thereby removing the small molecules from the patient's blood. Also, through the processes known as ultra-filtration and adsorption, water and middle molecules may pass through the semi-permeable membrane driven by a pressure gradient, thereby eliminating the excessive water and middle molecules from the patient's blood. As a result, the semi-permeable membrane that is used in the dialyzer and the way the semi-permeable membrane is used contribute on hemodialysis.
Conventional semi-permeable membranes can be divided into a conventional unmodified cellulosic membrane, a conventional semi-synthetic membrane and a conventional synthetic membrane.
Due to abundant surface hydroxyl groups, when the conventional unmodified cellulosic membrane is used in hemodialysis, the continuous contact with the patient's blood may easily induce activation of several inflammation pathways, such complements activation, white blood cells activation, platelets activation and coagulation, resulting in chronic inflammation, complements depletion and dysfunction of the inflammatory cells. Finally, the patient may suffer from an elevated opportunity of contracting cardiovascular diseases and infection.
The conventional semi-synthetic membrane is a modification of the conventional unmodified cellulosic membrane. Exposure of the surface hydroxyl groups is reduced by replacement or covering of the surface hydroxyl groups, thereby retarding white blood cells reduction due to the complements activation. However, the method for manufacturing the conventional semi-synthetic membrane is complicate, improving the cost for manufacturing the conventional semi-synthetic membrane thereof.
The conventional synthetic membrane with a larger average pore size can also be used in hemodialysis. However, because of the larger pore size, blood cells can easily diffuse through the conventional synthetic membrane, thereby decreasing the blood cell level in the blood. Moreover, if any endotoxins remain in the dialysates, the endotoxins probably may diffuse into the patient's blood, resulting infection of the patient.
In light of this, it is necessary to provide a biocompatible semi-permeable membrane.